1. Field of the Invention
The invention pertains to video monitor systems, and more particularly to a multi-tile display system that detects its physical arrangement.
2. Description of the Related Art
Video monitor systems are well known to the computer field. Originally adaptations of the television, the video monitor originally was a fairly straightforward device. It typically provided a text field of 80xc3x9724 characters, with data being received over a serial link and stored as ASCII or other types of codes. A controller would then display those characters on the video screen.
With graphical computing, however, the demands upon monitors increased. Personal computers were implemented with graphics controllers that provided a digital signal suitable for driving the monitor. The graphics controller board typically included video memory for mapping the image to be displayed and a cathode ray tube controller (CRTC) that repetitively read the video memory to provide appropriate digital signals for transmission to the monitor. With the early controllers, the data for each pixel was transmitted as a digital value to the monitor itself. This value was then passed through a digital-to-analog converter, so that an appropriate color was displayed for that pixel. Later, analog signals for each pixel of the image were instead transmitted, such as by using a video graphics adapter (VGA) controller.
With the increasing resolution of monitors, however, the speed of operation of the video controller and the CRTC and the bandwidth of the signal between the video controller and the monitor have entered into play as limiting factors. For example, 1280xc3x971024 resolution addressability monitor running at a 70 Hz refresh rate requires a bus bandwidth of 91.75 MHz pixel data rate. Those in the art will understand that resolution and addressability are often used as interchangeable terms. Increasing the display resolution necessarily results in a higher required data rate.
Further, modem systems sometimes employ multiple monitors for a single computer. Such configurations are sometimes used in concert to display a single image. Generally, however, the physical arrangement of the monitors must be manually configured into the display controller driver. Further, each monitor typically has a corresponding display controller in the computer system.
In a multi-tiled monitor system according to the invention, each monitor has detectors for determining the presence of adjacent monitors, as well as an orientation sensor to determine whether the monitor is in a portrait or landscape configuration. During set up, the monitors are instructed to transmit to adjacent monitors at an appropriate time, and the other monitors then attempt to detect an adjacent monitor that is transmitting. Using these adjacent monitor detectors, the video controller and associated driver determine the physical arrangement of monitors. In this way, a number of monitors can be xe2x80x9cstackedxe2x80x9d to form a large virtual monitor, and then automatically set up to display a signal image.
The adjacent monitor detectors and associated transmitters can take many forms. They can be infrared or visible light transmitters and receivers, they can be electrical contacts, they can be mechanical microswitches, radio frequency, or they can even be magnetic transmitters and receivers. Preferably, these adjacent monitor detectors and associated transmitters are coupled via a bus to a controlling computer system, either over the same bus that connects video controller, or, preferably, over lower speed bus such as a universal serial bus. Both buses, however, would typically be implemented in the same physical connection.